1. Introduction
The use of gaseous fuels for a variety of purposes is very popular. Gaseous fuels like LPG/Propane are widely used. The use of LPG/Propane for domestic cooking purposes is very common. LPG/Propane is bottled in a cylinder at the LPG plant and delivered to households for use. LPG is also used as fuel in vehicles. The gas is filled into the cylinder using sophisticated equipment through a valve. Sealing components ensure that gas does not leak from the cylinder. The filled cylinders are then transported to dealers for distribution, which are delivered to the households. In case of vehicles the CNG cylinders are re-filled at gas stations, which have CNG re-filling terminals.
The cylinder/tank are in the shape of a bottle. A metal valve is provided at the operative top end of the cylinder. A regulator is connected to the valve, which will regulate the pressure of the gas inside the cylinder and delivers to the appliances. The inlet of the regulator is fitted on the outlet of the valve fitted to the cylinder.
The quantity of gas present in the cylinder depletes as it is used. The empty cylinders are then returned to the distributor and sent to the bottling plant for refilling. After refilling, these cylinders/tanks are sent to the distribution centers, which in turn deliver the cylinders to households.
However as the amount of gas in the cylinder depletes, it is not possible to manually check the amount of gas remaining in the cylinder. If a person using such gas cylinders does not have a spare cylinder, it would be necessary for the person to wait until a new re-filled cylinder is provided.
Hence there was a need for a device, which would provide an indication of the amount of gas remaining in the cylinder.
2. Prior Art
Conventionally a pressure guage is used for measuring pressure changes. A pressure usually consists of a closed coiled tube connected to the chamber or pipe in which pressure is to be sensed. As the pressure increases the tube will tend to uncoil, while a reduced pressure will cause the tube to coil more tightly. This motion is transferred through a link to a gear train connected to an indicating needle. The needle deflects in a particular direction to indicate the change in pressure. However this type of a pressure guage can be used on site or for online applications. Using conventional pressure guages it is not possible to indicate pressure changes to a remote location.
U.S. Pat. No. 6,095,142 illustrates pressure indicating device for self contained breathing apparatus includes a piston arrangement which is responsive to the relative pressures of the supply and the pressure at the outlet of the first stage regulator to assume several different positions in the containment housing. Piston position is recognized by electronic circuitry and an LED display is lighted accordingly to provide a series of unique signals to the user, of the remaining quantity of breathing fluid. However this device cannot be used for indicating pressure in a LPG cylinder.
U.S. Pat. No. 6,606,903 illustrates a pressure indicating device for securing to a tire valve is disclosed. The device includes a flexible impermeable diaphragm on one wall of a permanently hermetically sealed chamber is pressurized to a given pressure. A mechanical linkage moves depending on whether the pressure in a tire to which the device is attached, is greater or less than that in the chamber which rotates a bicolored ball so that the color displayed provides a visual signal that indicates if the tire pressure is above or below the given pressure. However this device cannot be extended for indicating pressure in a gas cylinder.
This invention seeks to overcome the limitations of the prior art.
An object of this invention is to provide a simple, efficient and inexpensive device for indicating the pressure of the gas remaining in a cylinder.